TS3300 Datasheet, PDF (8/12 Pages) Touchstone Semiconductor Inc – 0.6-4.5VIN, 1.8-5.25VOUT, 3.5-uA, Low Input Voltage, High-Efficiency Boost + LDO

TS3300
THEORY OF OPERATION
The TS3300 is a power management product that
combines a high-efficiency boost regulator and an
output load switch into one package. The boost
regulator can operate from supply voltages as low as
0.6V and can deliver at least 75mA at 1.2VBI and
3VBO. Under no-load conditions, the boost regulator
exhibits a No-Load Input Supply Current of 10.8µA
that is actually drawn from the input source while the
output is within regulation.
At start-up, an internal low voltage oscillator in the
start-up control circuitry drives the gate of the internal
FET to charge the load capacitor. Once the output
voltage reaches approximately 1.1V, the main control
circuitry starts to operate.
With an adjustable peak inductor current, the TS3300
can provide up to 84% efficiency with a 1.2VBI and
3VBO. The input and output supply voltage range for
the boost regulator is from 0.6V to 3V and 1.8V to
3.6V, respectively.
The TS3300 can be operated in two different
configurations, Boost Only Configuration or
Boost + Output Load Switch Configuration. If the
Output Load Switch is not needed, it is recommended
to use the Boost Only Configuration, since the lowest
quiescent current is achievable this way.
Boost + Output Load Switch Operation
For Boost + Output Load Switch operation, please
refer to Figure 1 which displays the appropriate circuit
configuration. The Boost’s Output, BO, must be
connected to the Output Load Switch Input, REGIN.
The Output Load Switch is controlled by REGEN,
which is an Active Low Logic Input. The SWEN and
REGFB pins must be connected to REGIN. During
Boost + Output Load Switch operation, the Boost
Shutdown Control should not be used. The BEN pin
should be connected to analog ground. During this
mode of operation, the Output Load Switch will
require an added 1µA of Input Supply Current as
drawn from the input source. The anti-crush^TM feature
can be used during Boost + Output Load Switch
operation. The output load switch should not be used
as a load disconnect. Refer to Table 1 for the Output
Load Switch settings.
OUTPUT LOAD SWITCH FUNCTION
REG FB SW EN REGIN REG EN
FUNCTION
REG FB, SW EN, REGIN should
High
V_REGOUT=GND
(OFF State)
be connected to BO.
Low
V_REGOUT=V_BO
(ON State)
Table 1. Output Load Switch settings
Page 8
Figure 1. Boost + Output Load Switch Circuit Configuration
TS3300 Rev. 1.0